Scheme of the pharmacokinetic models proposed for the analysis of AmB concentrations in liver and spleen (A) and in kidney (B). k10, first-order elimination rate constant; k13 and k31, first-order distribution rate constants between plasma and liver, spleen, or kidney; kk31, first-order plasma to tissue (liver or spleen) distribution rate constant acting at times longer than Tlag; k12 and k21, first-order distribution rate constants between plasma and the peripheral compartment.